Automatic diazo copier

ABSTRACT

A recirculating arrangement for conveying an original sheet after initial registration with a copy sheet and duplication thereof back to an exposure position for registration with another copy sheet and duplication thereof. The recirculating arrangement comprises a stationary vacuum drum having a curved surface with an edge guide thereon. A plurality of spaced belts surround the drum and slide over the drum surface at an acute angle with respect to the edge guide. A plurality of rollers are mounted beneath the drum for driving the belts at the angle to the edge guide so that the original sheet will be urged against the edge guide when it is conveyed to the exposure position for positive registration of the original sheet with the copy sheet.

United States Patent [1 1 Ulmer 51 Jan. 9, 1973 [54] AUTOMATIC DIAZO COPIER [75] Inventor: Arnold G. Ulmer, Endicott, NY.

[73] Assignee: GAF Corporation, New York, NY.

[22] Filed: April 27, 1971 [21] Appl. No.: 137,874

[52] U.S. Cl. ..355/l09, 271/49, 271/74, 355/76, 355/104 [51] Int. Cl. ..G03b 27/12 [58] Field of Search ..355/64, 73, 76, 91, 104, 109; 271/46, 49, 59, 74

[56] 1 References Cited UNITED STATES PATENTS 2,435,099 1/1948 Pratt et al ..355/64 3,370,493 2/1968 Donley et al. ..271/49 X 3,288,464 11/1966 Thompson ..355/64 X 3,588,090 6/1971 Huston ..271/49 X OTHER PUBLICATIONS IBM Technical Disclosure Bulletin, Vol. 12, No. 7, Dec. 1969, pg. 943.

Primary Examiner-Samuel S. Matthews Assistant ExaminerRichard M. Sheer Attorney-Walter C. Kehm, Samson B. Leavitt and Martin Smolowitz [57] ABSTRACT A recirculating arrangement for conveying an original sheet after initial registration with a copy sheet and duplication thereof back to an exposure position for registration with another copy sheet and duplication thereof. The recirculating arrangement comprises a stationary vacuum drum having a curved surface with an edge guide thereon. A plurality of spaced belts surround the drum and slide over the drum surface at an acute angle with respect to the edge guide. A plurality of rollers are mounted beneath the drum for driving the belts at the angle to the edge guide so that the I original sheet will be urged against the edge guide when it is conveyed to the exposure position for positive registration of the original sheet with the copy sheet.

3'Claims, 8 Drawing Figures PATENTHJJM ems v 596 sum 1 or 3 ARNOLD a. 0mm

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PATENTEDJAN 9192a 3.709.596

sum 2 0r 3 AWOL'D ULNK PATENTED JAN 9 I975 SHEET 3 [1F 3 Fig. 4.

may 6?. DNER MM AUTOMATIC DIAZO COPIER This invention relates to dual roll feed automatic diazo copies, and more particularly to original recirculating devices for making multiple copies.

The invention provides an original recirculating device in which a selected original is carried over the curved surface of a stationary vacuum drum by spaced belts which areadvanced in unison along helical paths I on such surface so as to bias the original toward an edge guide on one side of the drum. Thus, the original is aligned for exact recopying when combined with the copy paper for making the same. A belt correcting roller system is located under the drum to feed the belts onto the drum surface at the correct angle of tilt, carry the belts away from the drum surface at the correct opposite angle of tilt, and reverse such tilt under the drum.

In the drawings:

FIG. 1 is a fragmentary view partly in elevation and partly in elevationand partly in cross-section of an automatic diazo copier having an original recirculating device illustrative of the invention.

FIG. 2 is a view mainly in cross-section of the device.

FIGS. 2a and 2b are fragmentary in elevation of the front and rear of the device.

FIG. 2c is a similar view of the rear set of conical rollers. FIG. 3 is an enlarged fragmentary view in elevation of the front portion of the device.

FIG. 3a is a fragmentary view in elevation of the helical path of the belt.

FIG. 4 is a fragmentary bottom plan view in direction arrow N of FIG. 2, showing the belt-tilt reversing system under the drum.

As shown in FIG. 1, the roll feed diazo copier includes an original or master recirculator l2 embodying the present invention. The recirculator 12 includes a vacuum drum 14 having a curved surface l6-between vertical flanges, constituting edge guide 18. Spaced belts 22 are urged to slide on the curved surface 16in helical paths which are inclined toward the edge guide 18, see FIG. 2a, by roller means 24 comprising an inclined front roller A, [FIG. 2,] and a first set of inclined conical rollers 26, FIG. 1 or B FIG. 2, one for each belt on a common tilted shaft B located under and to the rear of roller A.

The belts reverse the drum surface 16 between a series of slots 28 in the drum which have a negative internal pressure. This pressure is maintained via a vacuum connection 30, in order to gently hold the master or original on the moving belts 22, while the latter urge the original 32, FIG. 1, toward the edge guide 18 located to one side of the drum. As the original 32 advances towards the rear of the recirculator 12, it is transported through an inclined guide 35 and fed back into the horizontal way 36 for recopying.

At the same time, the belts 22 are carried under inclined rear roller G, then upwardly and over a .drive roller E, then downwardly and under a second set of conical rollers 38, on a common inclined roller D, and back under conical front rollers 26 and over roller A, back onto the drum surface. To assist the suction created on the surface of .the drum, the master 32 is sandwiched between the belts 22 and narrow strips of a plastic 34, such as antistatic polyester, which are attached to a guide member 39.

The belts 22 are driven by the drive roller E assisted by snubber rollers 40, and adjusted to proper tension by a tension roller C located under the belts 22 between the conical rollers 26 and 38.

Aligning of the master 32 prior to entering the printer section 42, is achieved by driving the belts 22 over the stationary drum 14 at an angle other than parallel to the edge guide of the drum. The belt 22 drive toward an edge guide 18 located on the drum. As

the master 32 emerges from the separator section.

(separator section not shown on FIG. 1), i.e., the copy paper following path to the developer section while master follows a path over belts of recirculator drum, the master is properly aligned and continues on its next cycle. Ejection of the master 32 is achieved after separation by conventional means. The tracking of the belts 22 being driven at an angle will be better understood by the following description.

Master paper leading edge 32 on actuating switch SW1 will start copy drive 44, FIG. 1. And as the leading edge of master 32 actuates switch SW2 a stepper switch (not shown) is energized for copy count. On last count, ejector 46 will raise and divert original 32 into drive out rollers 48.

In FIG. 20, let a be the angle the belts 22 are inclined to the surface 16 of the drum 14 with reference to the edge guide l 8.-Then rollers A and B are also positioned at an angle a with respect to the horizontal. As the belts 22 are endless, they will follow a helical pattern around the drum and, as a result rollers A and B must be compounded by equal angles of 0: [FIGS. 3 and 3a].

It follows from the foregoing that rollers D, E and 6 must also be compounded by equal angles of a. But as the belts 22 follow a helical path, these rollers will be compounded the reverse of rollers A and D, FIGS. 2a and 2b.

Referring to FIG. 4, let

L total length of belt 22.

D distance between rollers B and D.

a= angle belts 22 make with surface 16 of drum 14.

FIG. 2. length of belt 22 from roller B to D (around drum) displacement of belt from roller B to D R FIG. 4 (L-D sin a.

Tan [3 FIG. 4) [(L-D) sin a/D]/D In order to realign the belt 22 from B to D, the belt 22 is allowed to twist. The angle of twist is equal to angle [3". It will be noticed from FIG. 4 that the twist is equal and opposite between rollers B and D. The included taper of the rollers 26 and 38 is equal to 2 B".

With above conditions satisfied, the belts 22 enter roller E and leave roller A perfectly flat.

Roller C is a tension roller.

What is claimed is:

1. In an improved diazo copying machine, an original sheet recirculating arrangement for conveying an original sheet after initial registration with a copy sheet and duplication thereof back to an exposure position for registration with another copy sheet and duplication thereof, said recirculating arrangement including: a stationary drum mounted on a given axis having a curved surface with guide means adjacent one edge thereof, a series of aligned endless driving belts surrounding said drum and mounted for slidable engagement with said drum surface at an oblique angle with respect to said guide means, and roller means positioned beneath said drum and in engagement with said series of belts for driving said belts in concert with one another; said roller means having at least one roller positioned with respect to said drum axis for driving said belts along parallel paths with respect to one another and at said angle to said guide means so that the original sheet will be urged against said guide means when it is conveyed to the exposure'position for positive registration of the original sheet with a copy sheet for duplication of the original sheet.

2. The invention as defined by claim 1, in which said belts are equally spaced from one another,

the drum is provided with spaced slots located in the curved surface thereof between said belts, and vacuum means are provided within said drum for maintaining the interior of said drum at a negative pressure for lightly holding the original sheet on said driving belts. 3. The invention as defined by claim 2, in which means are provided comprising narrow strips of plastic material spaced slightly above the curved surface of said drum for urging the original sheet toward the belts for the purpose of assisting suction created on the surface of the drum by such negative pressure. 

1. In an improved diazo copying machine, an original sheet recirculating arrangement for conveying an original sheet after initial registration with a copy sheet and duplication thereof back to an exposure position for registration with another copy sheet and duplication thereof, said recirculating arrangement including: a stationary drum mounted on a given axis having a curved surface with guide means adjacent one edge thereof, a series of aligned endless driving belts surroundIng said drum and mounted for slidable engagement with said drum surface at an oblique angle with respect to said guide means, and roller means positioned beneath said drum and in engagement with said series of belts for driving said belts in concert with one another; said roller means having at least one roller positioned with respect to said drum axis for driving said belts along parallel paths with respect to one another and at said angle to said guide means so that the original sheet will be urged against said guide means when it is conveyed to the exposure position for positive registration of the original sheet with a copy sheet for duplication of the original sheet.
 2. The invention as defined by claim 1, in which said belts are equally spaced from one another, the drum is provided with spaced slots located in the curved surface thereof between said belts, and vacuum means are provided within said drum for maintaining the interior of said drum at a negative pressure for lightly holding the original sheet on said driving belts.
 3. The invention as defined by claim 2, in which means are provided comprising narrow strips of plastic material spaced slightly above the curved surface of said drum for urging the original sheet toward the belts for the purpose of assisting suction created on the surface of the drum by such negative pressure. 